Hemapheresis refers to the separation of blood into one or more of its components or fractions such as red cells, white cells, platelets and plasma. In typical hemapheresis procedures, whole blood is withdrawn from a donor or patient, anticoagulant is added to the withdrawn whole blood and one or more desired components or fractions are separated from the anticoagulated whole blood.
In hemapheresis procedures, blood is withdrawn from a donor or patient through a needle that is inserted into the vein of the donor or patient. The needle communicates with tubing through which the blood flows (often with the aid of pumps) to a device that separates the blood into its components or fractions. The separation device is often housed in an instrument that controls and regulates many aspects of the hemapheresis procedure (e.g. flow rates). Hemapheresis procedures and systems that utilize an instrument and/or device that separates blood into its components without significant operator intervention are often referred to as "automated" procedures and systems.
Instruments used to perform automated hemapheresis procedures typically include a reusable hardware portion and a disposable tubing portion intended for one-time use only. The hardware portion may include pumps, such as peristaltic pumps for (1) withdrawing whole blood from a donor or patient, (2) introducing blood or blood components into a separation device for separating blood into its components and (3) withdrawing one or more blood components from the separation device for subsequent use or for return to the donor or patient. Either the hardware portion or the disposable tubing portion may include the separation device which, for example, can be a rotating centrifuge as described in U.S. Pat. No. 4,146,172 or a rotating membrane as described in U.S. Pat. No. 4,753,729.
The disposable tubing portion typically includes, among other things, the plastic tubing which transports the blood and/or blood components to and from the donor or patient and to and from the separation device. If a desired blood component is to be collected, the disposable tubing portion may also include plastic bags for collecting the desired blood component(s). Typically, the segments of the tubing are threaded over and engaged by the peristaltic pumps of the instrument. Peristaltic pumps include rotating members (rotors) driven by motors. Rotation of the pump rotors squeezes the tubing and consequently draws and pushes the blood or blood components through the tubing and through the system.
In the early days of automated hemapheresis, tubings of the disposable set were threaded over the individual pump rotors one at a time by the instrument operator. For example, in the Aminco (later Fenwal) Celltrifuge.RTM. Blood Cell Separator, tubing segments were individually threaded over six peristaltic pump rotors. Similarly, in the IBM/Cobe 2997, the individual tubing segments were threaded over six pump rotors. This required great care on the part of the operator who had to ensure that the correct tubing segment was mated with the correct pump rotor and that the tubing was properly loaded onto the particular pump, thus, significantly adding to the time required to "set-up" the hemapheresis instrument.
More recently, efforts have been made to reduce the required set-up time of the hemapheresis instrument. Several of the currently commercially available automated hemapheresis instruments utilize disposable sets which have combined the tubing in prepackaged modules, which may include housings through which the tubing is routed, or other means which allow the tubing segments to be quickly and correctly mated with the proper pump rotor. Placement of the module, housing or other means (containing the tubing segments) on the hemapheresis instrument results in simultaneous placement of the tubing segments over the respective pump rotors and ensures that the correct tubing segment is mated with the appropriate pump rotor.
One example of such a prepackaged module with integral tubing segments is the one used with the CS3000 (and CS3000 Plus) made and sold by Baxter Healthcare Corporation of Deerfield, Ill. and described in U.S. Pat. No. 4,526,515 to DeVries (which is assigned to the assignee of the present application.) That patent describes a prepackaged fluid circuit module which includes a housing that can be removably positioned on a hemapheresis instrument in a predetermined relationship with respect to pump rotors. Tubing loops extending from the housing are disposed to interfit with selected pump rotors.
A similar device is used by the Cobe Spectra sold by Cobe Laboratories, Inc. of Lakewood, Colo. and described in U.S. Pat. No. 4,824,339 to Bainbridge. That patent describes a pump housing or cartridge having continuous flexible tubing with U-shaped loops integral with the housing. The tubing loops mate with specific peristaltic pump rotors on the face of the Spectra instrument.
Another example of a disposable tubing set that includes an apparatus for holding tubing segments is the set used with the Mini-Autopheresis-C.RTM., also made and sold by Baxter Healthcare Corporation and described in, for example, U.S. Pat. No. 5,460,493 (which patent is also assigned to the assignee of the present application and which is incorporated by reference herein.) There, the disposable tubing set includes a tubing "organizer" in the form of a plastic rectangular frame. The frame is provided with slots for holding various tubing segments in a desired orientation. The frame is placed on the face of the instrument in such a way that the tubing segments are mated with particular pump rotors located on the face of the instrument. Another portion of the frame holds other tubing segments of the disposable tubing set in place so that when the frame is placed on the instrument, those tubing segments are mated with specific clamping devices on the instrument.
The tubing organizer described in U.S. Pat. No. 5,460,493 provides an efficient and inexpensive way of reducing the set-up time of the hemapheresis instrument. The disposable tubing set is preassembled at a factory where the tubing segments are manually inserted into the appropriate slots. As shown in the top figure of FIG. 11 of U.S. Pat. No. 5,460,493, the circular slots of the organizer frame include openings to allow the tubing to be inserted into the slots. However, because the openings are smaller than the diameter of the tubing, the tubing segments must be stretched, pinched and pushed into the slot to ensure proper placement. Occasionally, if the tubing has not been firmly placed within the slot, the tubing segment may become dislodged from the slot (leaving it to the hemapheresis instrument operator to reinsert the tubing into the appropriate slots) or the tubing may remain partially pinched or occluded.
Accordingly, the present invention is directed to a disposable tubing set having an organizer frame which includes the benefits of the earlier tubing organizer frame and improves the ease of assembly by eliminating the need to pinch, stretch and push the tubing into place. The present invention also improves the reliability of the frame by minimizing the risk that the tubing segments will become dislodged prior to use or pinched by the organizer frame.